INDIVIDUAL WELFARE WHEN CONSUMERS CAN SHOP FOR HEALTH INSURANCE
研究了《平价医疗法案》下消费者可自由更换健康保险政策时，医疗价格下降对个人道德风险福利的影响，发现内生政策选择会改变福利结果，可能导致福利损失增加。
The statewide system of health insurance exchanges established by the Affordable Care Act (ACA) of 2010 will allow millions of U.S. citizens to change their health care policies more easily than they can switch automobile or homeowner insurance coverages, because deniability based on prior claim history is illegal. Focusing on this consumer endogeneity of health insurance policy choice, we examine the individual moral hazard welfare implications of a reduction in the price of medical care, which is a potential consequence of the ACA . We show that endogenous policy choice plays a key role in determining the welfare outcome. While moral hazard welfare improvement is not precluded, a distinctly possible outcome is that the consumer revises his/her choice of insurance policy so as to retain some portion of the reduction in expenditure risk caused by the medical care price decrease. In this event, moral hazard welfare loss is higher than it was before the price decrease, although the increased loss is tempered by the endogenous contract choice effect. This result resuscitates an old conventional wisdom.